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New Member

VoIP over Frame-Relay, Sub-interfaces

If I have a voice and a data PVC on seperate point-to-point sub-interfaces what QoS mechanism can I deploy that will interleave outbound packets from both PVC's?

I can obviously deploy QoS mechanisms on a per (sub-)interface basis but this will only operate on traffic within a particular PVC!

Any ideas?

New Member

Re: VoIP over Frame-Relay, Sub-interfaces

You can use FRF.12 or FRF.11 Annex C on PVC basis only.

I do not think you can interleave voice and data packets between different PVC’s.

Your large data packets will be fragmented within software queue and interleaved with voice packets at exit of software queue. Once packets leave software queue they will enter hardware/transmit queues which are in your case 2 FIFO queues for FR interface. There are ways if prioratising one of the dual FIFO queues.

Other option is to use FR PVC Interface Priority Queuing [PIPQ] which will prioritise Voice PVC over Data PVC. But unfortunately in this case you have to use strict priority queuing mechanism only, which can harm your data flows.

Your FR PIPQ will take precedence over FRF.12.

If you have low speed links why do you want to use different PVCs for voice and data anyway? Use single PVC and “smart queuing” mechanisms instead.